Replace Clutch Fluid

   The Pan has a hydraulic actuated clutch. "So what" I hear you say. The MOT bloke said the clutch had a funny bite as he had to move it around the garage. I too though the operation of the clutch was a little strange. Not enough to be worrisome just "not so". The Pan was registered in 2004. I suspect the clutch fluid has never been changed. Brake and clutch fluid (they are the same thing) absorb water over time and the fluid regrades. The hydrualic system can loose fluid or gain air from microscopic leaks. The fact the the clutch master cylinder resevoir cap screws were was seized backs up that theory. Click HERE to read the blog on replacing the screws in the clutch master cylinder.

   Changing the clutch fluid should not be that difficult; I had replaced the reservoir screws so they came out without and hitch. So long as can find where the bleed nipple for the slave cylinder is situated. I tend not to look in the owner's manual anymore but go straight to YouTube. There is some proper crap there but there is usually a nugget of gold in the videos. This link, click HERE, takes you to the chap who gave me a clue as to where the clutch slave cylinder bleed nipple was sited and whether is was an easy job. I had a feeling the bleed nipple would be hidden behind the faring somewhere. It seemed sensible to tackle the job whilst I had the belly pan off as part of the wiring upgrade for the Sat Nav and the USBs.

   The clutch bleed nipple is located on the near side just behind the bottom of the coolant expansion tank. It is easy to get to once the belly pan is removed. In the picture you can see I have a 10mm ring spanner on the bleed nipple and the tube leading down the catch bottle. Bleeding the clutch is just the same as bleeding brakes. With the nipple closed, pump the lever the build up pressure in the line. Undo the nipple, the pressure in the line is released and the air, if air is trapped, is released after a few cycles od pump and release. In my case I simply wanted to replace the fluid. with each pump and release a quantity of old fluid was pumped out of the system. After five or six cycles the master reservoir was runnign low on fluid so that was topped up. The topping up is down to ensure air is not introduced from in to the system from the top. The pump, release and top up cycle is continued until the fluid being pumped out at the bottom is clear like the fluid introduce to the top of the system. The master cylinder reservoir cap is refitted.

Although I did not ride rthe bike straigth away I could tell the replacing of the clutch fluid had had an effect. There was a lot less free movement in the lever and it felt firmer. I do not anticipate any operational difficulties. 

NB...

make sure in all this exercise you protect the paintwork from drips of clutch fluid. It eat paint for breakfast.

I had one other job to do then the belly pan was refitted.